1. Field of Invention
The present invention relates a heat dissipating apparatus, and in particular, to an air-extracting type heat dissipating apparatus.
2. Related Art
Because the performance of the electronic device is continuously promoted, it causes that the heat is increasingly produced when the electronic device runs. Hence, the efficiency of the heat dissipating apparatus is expected to be improved. Conventionally, the air-extracting type heat dissipating apparatus of fans is commonly used. However, the efficiency of heat dissipation of single fan is poor due to its low inhaled air volume.
Therefore, in order to improve the heat-dissipating efficiency, the conventional air-extracting type heat-dissipating apparatuses 1a and 1b as shown in FIG. 1A and FIG. 1B individually have two fan bodies 11 connected in series and in parallel, respectively, and they have power supply apparatuses 12a and 12b respectively for driving the fan bodies 11 of the air-extracting type heat-dissipating apparatuses 1a and 1b. However, the space to dispose two of the fan bodies 11 is great, and the power supply apparatus 12a and 12b also have the requirement of dissipating the heat generated by themselves. But, disposing extra heat dissipating for the power supply apparatus 12a and 12b not only is restricted by the insufficient interior space but also increases the production cost.
Besides, as shown in FIG. 2, another conventional air-extracting type heat-dissipating apparatus 2 has a fan body 21 and a power supply apparatus 22, and openings 211 are disposed on the positive pressure side (air-exhausting side) of the casing of the fan body 21. Such that, the exhausted air can be diverted through the openings 211 on the casing of the fan body 21 so as to dissipate the heat source of the power supply apparatus and electronic device. However, diversion of the air results in not only reducing the heat dissipating efficiency of the air-extracting type heat dissipating apparatus 2 of the electronic device, but also increasing the noise level as the air-extracting type heat-dissipating apparatus 2 runs.
Hence, it has been an important issue to provide an air-extracting type heat dissipating apparatus capable of increasing the heat dissipating efficiency instead of increasing the noise level.